Multiphase voltage regulator with multiple voltage sensing locations

ABSTRACT

A voltage regulator dynamically adjusts the voltage distribution on a voltage rail based on multiple feedback measurements. The voltage regulator provides electrical power to a voltage rail at multiple power supply locations along the voltage rail. The voltage regulator obtains voltage measurements from multiple voltage sensing locations on the voltage rail and detects a spatially unequal voltage deviation in the voltage rail. The voltage regulator adjusts the electrical power provided to the voltage rail at each of the power supply locations to compensate for the spatially unequal voltage deviation in the voltage rail.

TECHNICAL FIELD

The present disclosure relates to voltage regulation systems.

BACKGROUND

Remote voltage sensing is a common and effective feedback mechanism usedin modern voltage regulator design. The voltage feedback enables aprecise voltage supply with the resistive drop in the current path. Atypical voltage regulator uses the remote sensing terminal to sense thevoltage at the load point and regulate the output power of the voltageregulator. This enables the voltage regulator to achieve higher outputperformance to the load.

Multiphase voltage regulator design typically uses multiple Field EffectTransistor (FET) stages, with different phases associated with each FET.A single voltage regulator may control each phase with a Pulse WidthModulation (PWM) controller to enable larger currents, smaller ripple,and a quicker response to supply a power rail in a circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of a voltage regulation system withmultiple voltage sensing points, according to an example embodiment.

FIG. 2 is a simplified block diagram of a multiphase voltage regulatorwith feedback from multiple voltage sensing points, according to anexample embodiment.

FIG. 3 is a simplified block diagram of voltage regulation system for apower plane with different load devices, according to an exampleembodiment.

FIG. 4 is a simplified block diagram of a voltage regulation system fora power plane providing power to a large area chip, according to anexample embodiment.

FIG. 5 is a flowchart illustrating operations for providing power to avoltage rail, according to an example embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

In one form, a method for dynamically adjusting the voltage distributionon a voltage rail based on multiple feedback measurements is provided.The method includes providing electrical power to a voltage rail at aplurality of power supply locations along the voltage rail. The methodalso includes obtaining a plurality of voltage measurements from acorresponding plurality of voltage sensing locations on the voltage railand detecting a spatially unequal voltage deviation in the voltage rail.The method further includes adjusting the electrical power provided tothe voltage rail at each of the plurality of power supply locations tocompensate for the spatially unequal voltage deviation in the voltagerail.

Example Embodiments

In a typical multiphase voltage regulation topology, multiple driversand corresponding Field Effect Transistors (FETs) form phases that areplaced in close proximity to one side of the load for the voltageregulator. The placement of the components may enable the voltageregulator Pulse Width Modulation (PWM) controller to provide each phasewith an equal current output. Providing a stable voltage source thatmaintains a static voltage difference in a dynamic, high currentsituation presents additional challenges without the added expense ofmore copper and capacitors.

Additionally, typical voltage regulators rely on a single voltagesensing node for each voltage rail. The voltage sensing node may by asingle terminal node sensing the high voltage side or a differentialnode sensing both the ground and the high voltage side. The techniquesdescribed herein provide for a multiphase voltage regulator implementingmore than one voltage sensing node to gather voltage data from variouspoints on the voltage rail, and using the voltage data to increase theperformance of the multiphase voltage regulator with separatelycontrolled phase currents.

According to the techniques described herein, a single voltage regulatorreceives feedback from multiple voltage sensing nodes on a singlevoltage rail. In some examples, the voltage sensing input pins may beclosely associated with PWM controller chip packages. In one example,the voltage regulator may integrate a PWM controller with drivers and/orMetal-Oxide Semiconductor FETs (MOSFETs). In these examples, multiplesets of voltage sensing traces may be connected to chip packages for onevoltage rail.

Each phase of the power supply may have a different duty cycle or outputcurrent/voltage level based on the different voltage measurements fromthe voltage sensing nodes. This enables the voltage regulator to bettershape the current path and whole power rail compensation representation.Some phases may be strongly associated with some of the voltage sensingnodes while other phases will be strongly associated with other voltagesensing nodes based on the locations of the phases relative to thelocation of the voltage sensing nodes.

In one example, a graph theory may be employed to model the voltagedistribution of the entire power plane and allow the voltage regulatorto adjust the voltage/current of separate phases and shape the voltagedistribution of the power plane. For instance, the voltage regulator mayactively maintain slightly different voltage levels at differentlocations on the same voltage rail.

Referring now to FIG. 1, a simplified block diagram illustratesmultiphase voltage regulator 100 that provides power to a voltage rail105. The voltage regulator 100 includes a feedback module 110, a controlmodule 120, and a power supply module 130. The voltage regulator mayalso include a processor 140, which may process instructions stored in amemory 150. The processor 140 may include one or more processingelements (e.g., hardware microprocessors) configured to perform one ormore of the functions of the feedback module 110, the control module120, and/or the power supply module 130. The memory 150 may be one ormore computer readable storage media, such as Random Access Memory(RAM), cache memory, a magnetic disk drive, a solid state hard drive, asemiconductor storage device, Read-Only Memory (ROM), ErasableProgrammable Read-Only Memory (EPROM), flash memory, or any othercomputer readable storage media that is capable of storing programinstructions or digital information. Instructions for at least some ofthe functionality of the feedback module 110, control module 120, and/orthe power supply module 130 may be stored in the memory 150 forexecution by the processor 140. A computer readable storage medium, asused herein, is not to be construed as being transitory signals per se,such as radio waves or other freely propagating electromagnetic waves,electromagnetic waves propagating through a waveguide or othertransmission media (e.g., light pulses passing through a fiber-opticcable), or electrical signals transmitted through a wire.

The power supply module 130 is configured to provide power to threepower supply points 160, 162, and 164, which may be positioned atdifferent places along the voltage rail 105. Three voltage sensing nodes170, 172, and 174 detect the voltage at three different places along thevoltage rail 105 and provide the feedback 180 to the feedback module 110in the voltage regulator 100. The current supplied to each power supplypoint 160, 162, and 164 may also be measured and reported back to thefeedback module 110 as feedback 190.

In one example, the voltage sensing nodes 170, 172, and 174 may belocated physically proximate the positions of the power supply points160, 162, and 164 along the voltage rail. In another example, the powersupply points 160, 162, 164 may comprise multiple phases of PWM signals.For instance, each power supply point 160, 162, 164 may be assigned adifferent phase of a PWM signal such that each power supply point 160,162, 164 is actively providing power to the voltage rail at differenttimes within the PWM cycle. Alternatively, some or all of the phases ofthe PWM signal may be grouped together at each of the power supplypoints 160, 162, 164. Each group of phases may be associated with one ofthe voltage sensing nodes 170, 172, 174.

Each voltage sensing node 170, 172, 174 senses a region of the voltagerail 105 and provides the voltage feedback 180 to the voltage regulator100. The voltage regulator 100 regulates the current/voltage based onthe data received from the voltage sensing nodes 170, 172, 174. Thecontrol module 120 may cause the power supply module 130 to separatelyadjust the output current, output voltage, and/or duty cycle for eachpower supply point 160, 162, and 164. For instance, one or more of thepower supply points 160, 162, or 164 may be placed adjacent to loads(e.g., processor chip, memory module, etc.) that draws different amountsof current, either statically or dynamically. Placement of the powersupply points 160, 162, 164 and monitoring the voltage sensing nodes170, 172, 174 enables the control module 120 adjust the current/voltagebased on the actual power draw of nearby load devices.

Referring now to FIG. 2, one example of a multiphase voltage regulator100 is shown. The multiphase voltage regulator 100 includes a voltagefeedback module 210, a current feedback module 215, control logic 220,and PWM driver module 230. In one example, the control logic 220includes a Proportional/Integral/Derivative (PID) control logic that istuned to maintain a nominal voltage on the voltage rail.

The PWM driver module 230 generates a plurality of PWM signals 240(1),240(2), . . . , 240(N), which provide electrical power to a voltagerail. In one example, the PWM signals 240(1), 240(2), . . . , 240(N) aregenerated with a different phase, e.g., to smooth out the power profilebeing sent to the voltage rail. Typically, the combination of the PWMsignals 240(1), 240(2), . . . , 240(N) provides a constant, steadyvoltage level at the voltage rail.

The current in each phase of the PWM signals 240(1), 240(2), . . . ,240(N) is measured and provided to the current feedback module 215 ascurrent feedback 250(1), 250(2), . . . , 250(N). Additionally, thevoltage at a number of different points along the voltage rail ismeasured and returned to the voltage feedback module 210 as voltagefeedback 260(1), 260(2), . . . , 260(M). In one example, each voltagefeedback 260(1), 260(2), . . . , 260(M) may be a single endedmeasurement, a differential measurement, or other type of measurement.

Referring now to FIG. 3, an example implementation of a voltageregulation system 300 is shown with voltage regulator 100 providingpower to a voltage rail 105. In the system 300 the voltage rail 105 is apower plane that provides power to a processor chip 310 via power pins315. The voltage rail 105 also provides power to memory modules 320,330, and 340. In one example, the memory modules 320, 330, and 340 maybe includes one or more memory chips. For instance, each memory module320, 330, and 340 may comprise a pair of Double Data Rate 4 (DDR4)Registered Dual In-line Memory Modules (RDIMMs).

The voltage regulator 100 provides a first phase of electrical power viaa driver 350 and a power FET 355 positioned near the processor 310. Thevoltage regulator 100 provides a second phase of power via a driver 360and a power FET 365 positioned near the memory modules 320 and 330. Thevoltage regulator 100 provides a third phase of power via a driver 370and a power FET 375 positioned near the memory module 340. To monitorthe voltage level in the voltage rail 105, voltage sensing nodes 380,382, and 384 are positioned along the voltage rail 105. The voltagesensing node 380 is positioned near the power FET 355 and the processor310. The voltage sensing node 382 is positioned near the power FET 365and the memory modules 320 and 330. The voltage sensing node 384 ispositioned near the power FET 375 and the memory module 340.

In the voltage regulation system 300, the voltage regulator 100 controlsthree phases of PWM signals. Each voltage sensing node (also referred toas a voltage sensing point) 380, 382, and 384 is placed near one loadpoint to provide precise voltage sensing of the nearby load. The voltageregulator 100 strongly associates each particular phase of the PWMsignal with the voltage sensing point that is closest to the particularphase, and weakly associates the particular phase of the PWM signal withthe other voltage sensing points, which are further from the particularphase. Specifically, the voltage regulator 100 strongly associates thevoltage sensing point 380 with the signal provided to the driver 350,and weakly associates the voltage sensing point 380 with the signalprovided to the drivers 360 and 370. Similarly, the voltage regulator100 strongly associates the voltage sensing point 382 with the signalprovided to the driver 360, and weakly associates the voltage sensingpoint 382 with the signal provided to the drivers 350 and 370. Further,the voltage regulator 100 strongly associates the voltage sensing point384 with the signal provided to the driver 370, and weakly associatesthe voltage sensing point 384 with the signal provided to the drivers350 and 360.

The three phases are spread along the power plane rather than placed ata single point, ensuring that each phase has a different current path toeach load. With the voltage measurement from the different voltagesensing points 380, 382, and 384, the voltage regulator 100 mayseparately regulate the duty cycle and/or output current/voltage foreach phase to provide voltage compensation at specific locations.Additionally, adjusting the duty cycle and/or output voltage/current tocompensate for a voltage deviation in one location of the power planemay have minimal impact on the voltage of other locations of the powerplane.

In one example, the processor 310 may draw significantly more currentthan the memory modules 320, 330, and 340. The voltage sensing node 380near the processor 310 would detect a lower voltage than the voltagesensing nodes 382 and 384. The voltage regulator 100 detects the lowervoltage, i.e., a higher voltage deviation, at the voltage sensing point380 and increases the current output of the phase near the voltagesensing point 380, i.e., the first phase with the driver 350 and powerFET 355, up to a predetermined current limit of the phase. The voltageregulator 100 may also increase the current in the other two phases inproportion to the current increase of the first phase until the firstphase reaches the phase current limit.

In some cases, the voltage drop at the voltage sensing point 380 may belarge enough that the first phase reaches the phase current limitwithout compensating for the voltage drop. If the components of thefirst phase approach a current limit for the phase, the voltageregulator may begin to increase the current of the other two phases.

At other times, the memory modules 320, 330, and/or 340 may drawsignificantly more current than the processor 310, and the voltage atthe voltage sensing points 382 and/or 384 may be lower than the voltageat the voltage sensing point 380. The voltage regulator 100 detects thevoltage deviation and enables more current to the second phase and/orthird phase near the voltage sensing points 382 and/or 384. In this way,the voltage deviation at the voltage sensing point 382 and/or 384 iscorrectly compensated with less impact on the processor 310.

In another embodiment, large scale chips (e.g., microprocessors) maydraw significant amounts of current from power pins placed in differentlocations of the voltage. Due to the inherent resistance in the voltagerail, the voltage provided to power pins close to power supply driversmay vary significantly from the voltage provided to power pins far fromthe power supply drivers.

The voltage regulator faces challenges in providing a voltage valuewithin a specified range to any portion of a large scale chip,particularly as chips draw an increasing amount of current from thevoltage rail. If the voltage rail provides a voltage level that is toolow for one of the power pins in a large scale chip, then the chip maynot be able to correctly distinguish between logic 0 and logic 1 values.Conversely, if the voltage rail provides a voltage level that is toohigh, then the chip may suffer from thermal issues. A narrower specifiedrange for the voltage of the voltage rail allows for increased thermalefficiency and less design complexity of the chip.

Referring now to FIG. 4, a voltage regulation system 400 is shown toprovide consistent voltage to multiple points in a large scale, highpower chip 410 via a voltage rail 105. The voltage regulator 100provides electrical power in five phases to each of three banks of powersupply drivers surrounding the chip 410. In the left bank, the voltageregulator 100 provides one phase of the PWM power signal to a driver 420coupled to a power FET 421. Additionally, the voltage regulator 100provides additional phases of the PWM power signal on the left bank ofpower supply drivers to drivers 422, 424, 426, and 428 coupled to powerFETs 423, 425, 427, and 429, respectively.

Similarly, in the top bank, the voltage regulator 100 provides one phaseof the PWM power signal to a driver 430 coupled to a power FET 431.Additionally, the voltage regulator 100 provides additional phases ofthe PWM power signal on the top bank of power supply drivers to drivers432, 434, 436, and 438 coupled to power FETs 433, 435, 437, and 439,respectively. Further, in the right bank, the voltage regulator 100provides one phase of the PWM power signal to a driver 440 coupled to apower FET 441. Additionally, the voltage regulator 100 providesadditional phases of the PWM power signal on the right bank of the powersupply drivers to drivers 442, 444, 446, and 448 coupled to power FETs443, 445, 447, and 449, respectively. The voltage regulator 100 measuresthe voltage level at voltage sensing points 450, 452, and 454, whichcorrespond to the left, top, and right sides of the chip, respectively.

The voltage regulator 100 strongly correlates the signals for the leftbank (i.e., drivers 420, 422, 424, 426, and 428) with the voltagemeasured at the voltage sensing point 450. Similarly, the voltageregulator strongly correlates the signals for the top bank (i.e.,drivers 430, 432, 434, 436, and 438) with the voltage measured at thevoltage sensing point 452. Likewise, the voltage regulator 100 stronglycorrelates the signals for the right bank (i.e., drivers 440, 442, 444,446, and 448) with the voltage measured at the voltage sensing point454. The voltage regulator 100 may continuously monitor the voltagevalues measured at the voltage sensing points 450, 452, and 454. Thevoltage regulator may adjust the PWM signals to the drivers based on acomparison between the voltage values measured at the voltage sensingpoints 450, 452, and 454 and a target value for the voltage rail, aswell as based on the difference between the measured voltages values.

In one example, with the chip 410 drawing a large static current load,the voltage regulator 100 may adjust each bank of power supply driversto move all three voltage sensing points 450, 452, and 454 to a targetvoltage value. The current provided by each bank of power supply driversmay differ depending on where in the chip 410 the power pins are drawingcurrent. If the voltage sensing point 450 measures a lower voltage thanthe voltage sensing points 452 and 454, then the voltage regulator 100may adjust the left bank (e.g., one or more of drivers 420, 424, 426,and 428) to provide more current than the top bank or the right bank. Inother words, each bank of power supply drivers may provide a differentamount of current due to different locations and different current pathloss to the power pins of the chip 410.

In another example, with the chip 410 drawing a dynamic load, some ofthe power pins of the chip 410 may draw different amount of current atdifferent times. When certain power pins of the chip 410 draw morecurrent, the voltage of the voltage rail 105 drops in the vicinity ofthe power pins. The voltage sensing points 450, 452, and 454 detect thevoltage drop and the voltage regulator 100 enables the phases of thebank nearest the voltage sensing point with the lowest voltage toincrease its current output. The voltage regulator 100 may also reducethe amount of current provided by the banks of power supply driversfurthest from the power pin drawing the most current from the voltagerail 105. Providing more current from the bank of power supply driversclosest to the power pin drawing the most current at any particular timemay reduce the size of the capacitors needed in the total power design.

In a further example, the voltage/current supplied by each phase may becorrelated with the voltage sensing nodes in a matrix. A graph theorymay be used to determine the duty cycle and/or current/voltage output byeach phase. In other words, the voltage sensing points may determine avoltage distribution in the voltage rail 105, and the voltage regulator100 may drive individual phases to shape the voltage distributionthroughout the voltage rail 105 to compensate for any voltage deviationdetected by the voltage sensing nodes.

In one example, the voltage regulator 100 may shape the voltagedistribution to be a constant voltage level throughout the entirevoltage rail 105. Alternatively, the voltage regulator may shape thevoltage distribution to be uneven, e.g., based on expected current drawsfrom different power pins. The voltage regulator 100 may determine theoptimal voltage distribution for the voltage rail based on thedistribution of load devices drawing power from the voltage rail, theexpected use conditions, and/or the measured feedback voltages.

Different current provided to different phases may cause uneven thermaleffects, for which the voltage regulator 100 may compensate. As long asthe voltage regulator 100 monitors the current to each phase and thethermal conditions of each phase, the voltage regulator 100 may maintainan optimal balance between current and thermal considerations.

In some examples, the voltage regulator 100 may integrate multiplecomponents, including a PWM controller (e.g., PWM driver module 230 asshown in FIG. 2), FET drivers (e.g., drivers 350, 360, and 370 in FIG.3), power FETs (e.g., FET 355, 365, and FET 375 in FIG. 3), or otheractive or passive components (e.g., capacitors, inductors, etc.). Inother examples, only the FET drivers and FETs are integrated. In stillother examples, the PWM controller may be integrated with the FETdrivers.

Referring now to FIG. 5, a flowchart is shown that depicts operations ofa voltage regulator (e.g., voltage regulator 100) in an example process500 to provide a stable voltage rail. At 510, the voltage regulatorprovides electrical power to a plurality of power supply locations on avoltage rail. In one example, the voltage regulator is a multiphasevoltage regulator that provides PWM signals to multiple power supplydrivers. Each power supply driver may include a separate phase of PWMsignal to enable different power supply drivers to be active atdifferent times.

At 520, the voltage regulator obtains a plurality of voltagemeasurements from a plurality of different voltage sensing locations inthe voltage rail. In one example, the voltage sensing locations may beclose to the locations of one or more power supply locations. In anotherexample, the voltage sensing locations may be close to the locations ofone or more load devices that are powered from the voltage rail. Basedon the plurality of voltage measurements, the voltage regulator detectsa spatially unequal voltage deviation in the voltage rail at 530. In oneexample, one of the load devices may draw a significant amount ofcurrent, lowering the voltage in the vicinity of the load devicerelative to the voltage in the remainder of the voltage rail.

At 540, the voltage regulator adjusts the electrical power provided tothe plurality of power supply locations to compensate for the spatiallyunequal voltage deviation in the voltage rail. In one example, thevoltage regulator may adjust the phase of a power supply locationsclosest to the voltage deviation to minimize the voltage deviation andmaintain a predetermined value of the voltage rail.

In summary, the techniques presented herein provide for a voltageregulator that receives feedback from multiple voltage sensing locations(multiple remote voltage sense nodes) to improve performance under highcurrent load for a single power rail voltage regulator. The voltageregulator enables distributed FET phase allocation to improve voltageregulator efficiency and performance. In particular, the techniquespresented herein enable the voltage regulator to actively adjust eachpower phase current for optimal power efficiency and performance.Multiple voltage sensing points provide a more accurate detection of thevoltage distribution throughout the entire power plane.

In one embodiment, the techniques presented herein enable activelyadjusting each different current path from multiple FET phases to asingle power rail to optimize power efficiency and performance. Each FETphase current may be strongly or weakly correlated with differentvoltage sensing nodes based on the locations of the FET phase relativeto the location of the voltage sensing node.

Additionally, the techniques presented herein reduce cost by minimizingcopper and/or capacitance requirements. Further, the techniquespresented herein enable a tighter tolerance for voltage rails, which mayallow for chips that operate at a lower voltage to conserve power. Inanother embodiment, the voltage regulator presented herein may activelymaintain slightly different voltage levels at different locations on thesame power rail to allow for different design margins in chip design.When phases are spread along the voltage rail, multiple voltage sensingnodes may enable the voltage regulator to provide the phases with anoptimal amount of current near each load on the voltage rail, minimizingresistive losses, especially at high current levels.

In one form, a method for dynamically adjusting the voltage distributionon a voltage rail based on multiple feedback measurements is provided.The method includes providing electrical power to a voltage rail at aplurality of power supply locations along the voltage rail. The methodalso includes obtaining a plurality of voltage measurements from acorresponding plurality of voltage sensing locations on the voltage railand detecting a spatially unequal voltage deviation in the voltage rail.The method further includes adjusting the electrical power provided tothe voltage rail at each of the plurality of power supply locations tocompensate for the spatially unequal voltage deviation in the voltagerail.

In a specific embodiment, adjusting the electrical power provided to thevoltage rail comprises minimizing the spatially unequal voltagedeviation in the voltage rail.

In another specific embodiment, the method also includes associatingeach of the plurality of voltage sensing locations with one or more loaddevices configured to draw power from the voltage rail. Additionally,adjusting the electrical power provided to the voltage rail may comprisedetermining an optimal voltage distribution along the voltage rail basedon a distribution of the one or more load devices and providingdiffering amounts of electrical power to the plurality of power supplylocations on the voltage rail.

In a further specific embodiment, providing electrical power to thevoltage rail comprises driving a plurality of PWM signals with differentphases. Additionally, the method may also include associating at leastone phase of the plurality of PWM signals with each of the plurality ofpower supply locations. Further, adjusting the electrical power providedto the voltage rail may comprise adjusting one or more of a duty cycle,an output current, or an output voltage for at least one phase of theplurality of PWM signals.

In another form, an apparatus comprising a voltage sensing module, acontrol module, and a power supply module is provided. The voltagesensing module is configured to obtain a plurality of voltagemeasurements from a corresponding plurality of voltage sensing locationson a voltage rail. The control module is configured to detect aspatially unequal voltage deviation in the voltage rail based on theplurality of voltage measurements. The power supply module is configuredto provide electrical power to the voltage rail at a plurality of powersupply locations along the voltage rail. The power supply module is alsoconfigured to adjust the electrical power provided to the voltage railat each of the plurality of power supply locations to compensate for thespatially unequal voltage deviation in the voltage rail.

In another form, a system comprising a voltage rail and a multiphasevoltage regulator is provided. The voltage rail is electricallyconnected to one or more load devices. The multiphase voltage regulatoris configured to provide electrical power to the voltage rail at aplurality of power supply locations along the voltage rail. Themultiphase voltage regulator is also configured to obtain a plurality ofvoltage measurements from a corresponding plurality of voltage sensinglocations on the voltage rail and detect a spatially unequal voltagedeviation in the voltage rail. The multiphase voltage regulator isfurther configured to adjust the electrical power provided to thevoltage rail at each of the plurality of power supply locations tocompensate for the spatially unequal voltage deviation in the voltagerail.

Computer readable program instructions for carrying out operations ofthe present embodiments may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Python, C++, or the like, and procedural programminglanguages, such as the “C” programming language, Python or similarprogramming languages. In some embodiments, electronic circuitryincluding, for example, programmable logic circuitry, field-programmablegate arrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the presented embodiments.

Aspects of the present embodiments are described herein with referenceto flowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to presentedembodiments. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variouspresented embodiments. In this regard, each block in the flowchart orblock diagrams may represent a module, segment, or portion ofinstructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments have been presented forpurposes of illustration, but are not intended to be exhaustive orlimited to the embodiments disclosed. Many modifications and variationswill be apparent to those of ordinary skill in the art without departingfrom the scope and spirit of the described embodiments. The terminologyused herein was chosen to best explain the principles of theembodiments, the practical application or technical improvement overtechnologies found in the marketplace, or to enable others of ordinaryskill in the art to understand the embodiments disclosed herein.

1. A method comprising: driving a plurality of Pulse Width Modulation(PWM) signals with different phases to provide electrical power to avoltage rail at a plurality of power supply locations along the voltagerail; obtaining a plurality of voltage measurements from a correspondingplurality of voltage sensing locations on the voltage rail; detecting aspatially unequal voltage deviation in the voltage rail based on theplurality of voltage measurements; and adjusting the electrical powerprovided to at least one of the plurality of power supply locations ofthe voltage rail by adjusting at least one of the plurality of PWMsignals to compensate for the spatially unequal voltage deviation in thevoltage rail.
 2. The method of claim 1, wherein adjusting the electricalpower comprises minimizing the spatially unequal voltage deviation inthe voltage rail.
 3. The method of claim 1, further comprisingassociating each of the plurality of voltage sensing locations with oneor more load devices configured to draw power from the voltage rail. 4.The method of claim 3, wherein adjusting the electrical power comprises:determining an optimal voltage distribution along the voltage rail basedon a distribution of the one or more load devices; and providingdiffering amounts of electrical power to the plurality of power supplylocations on the voltage rail.
 5. (canceled)
 6. The method of claim 1,further comprising associating at least one phase of the plurality ofPWM signals with each of the plurality of power supply locations.
 7. Themethod of claim 6, wherein adjusting the electrical power comprisesadjusting one or more of a duty cycle, an output current, or an outputvoltage for at least one phase of the plurality of PWM signals.
 8. Anapparatus comprising: a voltage sensing module configured to obtain aplurality of voltage measurements from a corresponding plurality ofvoltage sensing locations on a voltage rail; a control module configuredto detect a spatially unequal voltage deviation in the voltage railbased on the plurality of voltage measurements; and a power supplymodule configured to: drive a plurality of Pulse Width Modulation (PWM)signals with different phases to provide electrical power to the voltagerail at a plurality of power supply locations along the voltage rail;and adjust the electrical power provided to at least one of theplurality of power supply locations of the voltage rail by adjusting atleast one of the plurality of PWM signals to compensate for thespatially unequal voltage deviation in the voltage rail.
 9. Theapparatus of claim 8, wherein the control module is configured to causethe power supply module to adjust the electrical power by minimizing thespatially unequal voltage deviation in the voltage rail.
 10. Theapparatus of claim 8, wherein the control module is further configuredto associate each of the plurality of voltage sensing locations with oneor more load devices configured to draw power from the voltage rail. 11.The apparatus of claim 10, wherein the control module is configured to:determine an optimal voltage distribution along the voltage rail basedon a distribution of the one or more load devices; and cause the powersupply module to provide differing amounts of electrical power to theplurality of power supply locations on the voltage rail.
 12. (canceled)13. The apparatus of claim 8, wherein the control module is furtherconfigured to associate at least one phase of the plurality of PWMsignals with each of the plurality of power supply locations.
 14. Theapparatus of claim 13, wherein the power supply module is configured toadjust the electrical power by adjusting one or more of a duty cycle, anoutput current, or an output voltage for at least one phase of theplurality of PWM signals.
 15. A system comprising: a voltage railconfigured to be electrically connected to one or more load devices; anda multiphase voltage regulator configured to: drive a plurality of PulseWidth Modulation (PWM) signals with different phases to provideelectrical power to the voltage rail at a plurality of power supplylocations along the voltage rail; obtain a plurality of voltagemeasurements from a corresponding plurality of voltage sensing locationson the voltage rail; detect a spatially unequal voltage deviation in thevoltage rail based on the plurality of voltage measurements; and adjustthe electrical power provided to at least one of the plurality of powersupply locations of the voltage rail by adjusting at least one of theplurality of PWM signals to compensate for the spatially unequal voltagedeviation in the voltage rail.
 16. The system of claim 15, wherein themultiphase voltage regulator is configured to adjust the electricalpower by minimizing the spatially unequal voltage deviation in thevoltage rail.
 17. The system of claim 15, wherein the multiphase voltageregulator is further configured to associate each of the plurality ofvoltage sensing locations with at least one of the one or more loaddevices.
 18. The system of claim 17, wherein the multiphase voltageregulator is configured to adjust the electrical power by: determiningan optimal voltage distribution along the voltage rail based on adistribution of the one or more load devices; and providing differingamounts of electrical power to the plurality of power supply locationson the voltage rail.
 19. (canceled)
 20. The system of claim 15, whereinthe multiphase voltage regulator is further configured to associate atleast one phase of the plurality of PWM signals with each of theplurality of power supply locations.
 21. The method of claim 4, whereinthe optimal voltage distribution along the voltage rail is uneven. 22.The apparatus of claim 11, wherein the optimal voltage distributionalong the voltage rail is uneven.
 23. The system of claim 18, whereinthe optimal voltage distribution along the voltage rail is uneven.